Geothermal energy is thermal energy in the Earth's crust. It combines energy from the formation of the planet and from radioactive decay. Geothermal energy has been exploited as a source of heat and/or electric power for millennia.
Geothermal heating is the direct use of geothermal energy for some heating applications. Humans have taken advantage of geothermal heat this way since the Paleolithic era. Approximately seventy countries made direct use of a total of 270 PJ of geothermal heating in 2004. As of 2007, 28 GW of geothermal heating capacity is installed around the world, satisfying 0.07% of global primary energy consumption. Thermal efficiency is high since no energy conversion is needed, but capacity factors tend to be low since the heat is mostly needed in the winter.
A binary cycle is a method for generating electrical power from geothermal resources and employs two separate fluid cycles, hence binary cycle. The primary cycle extracts the geothermal energy from the reservoir, and secondary cycle converts the heat into work to drive the generator and generate electricity.
The potential for exploiting geothermal energy in the United Kingdom on a commercial basis was initially examined by the Department of Energy in the wake of the 1973 oil crisis. Several regions of the country were identified, but interest in developing them was lost as petroleum prices fell. Although the UK is not actively volcanic, a large heat resource is potentially available via shallow geothermal ground source heat pumps, shallow aquifers and deep saline aquifers in the mesozoic basins of the UK. Geothermal energy is plentiful beneath the UK, although it is not readily accessible currently except in specific locations.
Geothermal power in Australia was at one time hoped to provide cost effect, renewable power for Australia. There are locations that have been shown to contain hot granites at depth which hold good potential for development of geothermal energy. Exploratory geothermal wells have been drilled to test for the presence of high temperature geothermal reservoir rocks and such hot granites were detected. However, all these projects have since been abandoned. A small geothermal plant in Queensland experienced problems during commissioning and as at May 2022, remains idle.
Geothermal energy was first used for electric power production in the United States in 1960. The Geysers in Sonoma and Lake counties, California was developed into the largest geothermal steam electrical plant in the world, at 1,517 megawatts. Other geothermal steam fields operate in the western US and Alaska.
Geothermal power is electrical power generated from geothermal energy. Technologies in use include dry steam power stations, flash steam power stations and binary cycle power stations. Geothermal electricity generation is currently used in 26 countries, while geothermal heating is in use in 70 countries.
Energy consumption across Russia in 2020 was 7,863 TWh. Russia is a leading global exporter of oil and natural gas and is the fourth highest greenhouse emitter in the world. As of September 2019, Russia adopted the Paris Agreement In 2020, CO2 emissions per capita were 11.2 tCO2.
Canada has substantial potential for geothermal energy development. To date, development has all been for heating applications. Canada has 103,523 direct use installations as of 2013. There is currently no electricity being generated from geothermal sources in Canada although substantial potential exists in the Canadian Cordillera. The most advanced project exists as a test geothermal-electrical site at the Mount Meager massif in British Columbia, where a 100 MegaWatt (MW) facility could be developed. Potential for enhanced geothermal energy systems (EGS) exists throughout Canada. There are six geothermal power and two direct use projects listed with the Canadian Geothermal Energy Association.
Japan has favorable sites for geothermal power because of its proximity to the Izu–Bonin–Mariana Arc. In 2007, Japan had 535.2 MW of installed electric generating capacity, about 5% of the world total. Geothermal power plays a minor role in the energy sector in the country: in 2013 it supplied 2596 GWh of electricity, representing about 0.25% of the country's total electricity supply.
Renewable energy in Russia mainly consists of hydroelectric energy. In 2010, the country was the sixth largest producer of renewable energy in the world, although it was 56th when hydroelectric energy was not taken into account. Some 179 TWh of Russia's energy production came from renewable energy sources, out of a total economically feasible potential of 1823 TWh. 16% of Russia's electricity was generated from hydropower, and less than 1% was generated from all other renewable energy sources combined. Roughly 68% of Russia's electricity was generated from thermal power and 16% from nuclear power.
Renewable energy in Armenia ranges from geothermal, hydroelectric, solar and wind energy in Armenia.
The Pauzhetskaya power station is located in the south-western part of the Kamchatka Peninsula, 30 kilometres (19 mi) east of Ozernovskij settlement, located on the coast of the Okhotsk Sea. The geothermal power plant was put into operation in 1966. The power plant has two 6 MW turbines of direct cycle and 2.5 MW binary turbine. The first steam turbine is designed for an inlet pressure of 1.2 bars and a steam flow rate of 24.2 kg/s. The second steam turbine is designed for an inlet pressure of 2.2 bars and a steam flow rate of 25.8 kg/s. The binary turbine is designed for a separated water flow rate of 118 kg/s at 120 °C. Presently, one steam turbine is in operation, while the other steam turbine is a reserve.
Mutnovskaya power station is a geothermal power plant. It is the largest geothermal power plant in Russia, 60 km south from the administrative center of Petropavlovsk-Kamchatka region, on the bank of the Falshivaya River. Its capacity is 50 MW. The plant is operated by Geotherm JSC, a subsidiary of PJSC RusHydro.
Hungary is a member of the European Union and thus takes part in the EU strategy to increase its share of renewable energy. The EU has adopted the 2009 Renewable Energy Directive, which included a 20% renewable energy target by 2020 for the EU. By 2030 wind should produce in average 26-35% of the EU's electricity and save Europe €56 billion a year in avoided fuel costs. The national authors of Hungary forecast is 14.7% renewables in gross energy consumption by 2020, exceeding their 13% binding target by 1.7 percentage points. Hungary is the EU country with the smallest forecast penetration of renewables of the electricity demand in 2020, namely only 11%.
The Karkar Geothermal Power Plant (Karkar GTPP) (Armenian: Կարկառի երկրաջերմաէլեկտրակայան) is a proposed geothermal power plant to be constructed in Armenia. The plant will be the first of its kind in Armenia and will be situated at the Karkar site in the southernmost province of Armenia, Syunik. Initial studies envisage the construction of a 28-30 MW capacity geothermal power plant with an annual electric output of 250 million kilowatt hours (kWh) according to data provided in 2016. The Karkar GTPP will allow for the production of heat to be used in the heating of greenhouses, residential buildings, and industrial sites. Commissioned in 2008-2009, the Karkar GTPP is a unique project in Armenia in that it does not possess an analogue in the region, and positively differs from other energy producing power plants in its renewability of resources, independence from imported energy sources, as well as its minimal environmental impact.
Renewable energy in South Africa is energy generated in South Africa from renewable resources, those that naturally replenish themselves—such as sunlight, wind, tides, waves, rain, biomass, and geothermal heat. Renewable energy focuses on four core areas: electricity generation, air and water heating/cooling, transportation, and rural energy services. The energy sector in South Africa is an important component of global energy regimes due to the country's innovation and advances in renewable energy. South Africa's greenhouse gas (GHG) emissions is ranked as moderate and its per capita emission rate is higher than the global average. Energy demand within the country is expected to rise steadily and double by 2025.
By the end of 2016 Austria already fulfilled their EU Renewables Directive goal for the year 2020. By 2016 renewable energies accounted to 33.5% of the final energy consumption in all sectors. The renewable energy sector is also accountable for hosting 41,591 jobs and creating a revenue of 7,219 million euros in 2016.
There is about 1 MW of geothermal heating of communal buildings and 3 MW of baths in Ukraine. But there is no geothermal electricity generation.
Solar augmented geothermal energy (SAGE) is an advanced method of geothermal energy that creates a synthetic geothermal storage resource by heating a natural brine with solar energy and adding enough heat when the sun shines to generate power 24 hours a day. The earth is given enough energy in one hour to provide all electrical needs for a year. Available energy is not the issue, but energy storage is the problem and SAGE creates effective storage and electrical power delivery on demand. This technology is especially effective for geothermal wells that have demonstrated inconsistent heat or idle oil or gas fields that have demonstrated the proper geology and have an abundance of solar.
